BiFC

BiFC, or Bimolecular Fluorescence Complementation, is a molecular biology technique used to study protein-protein interactions in living cells. The method involves splitting a fluorescent protein, such as GFP (Green Fluorescent Protein), into two non-fluorescent fragments. These fragments are individually fused to two proteins of interest. When the two proteins interact within a cell, the two fragments of the fluorescent protein are brought into close proximity, allowing them to reassemble into a functional fluorescent molecule. This reconstitution results in a detectable fluorescence signal, indicating a direct interaction between the proteins.

BiFC provides several advantages, including the ability to visualize interactions spatially within cellular compartments and in real-time. It is widely used for mapping protein interaction networks, studying signal transduction pathways, and analyzing dynamic cellular processes.

However, BiFC also has some limitations. The reassembly of fluorescent protein fragments can sometimes be irreversible, potentially capturing transient interactions as stable ones. Additionally, the formation of the fluorescent complex can influence the native function or localization of the proteins involved, leading to possible artifacts.

Overall, BiFC is a valuable tool in cell biology and biochemistry for investigating protein interactions, complementing other methods such as co-immunoprecipitation and Förster resonance energy transfer (FRET). Its ability to provide visual evidence of interactions within living cells has advanced our understanding of cellular processes at the molecular level.